Magento disable main category mouse over navigation

# view mouse over only for first sub-category
cp ./app/code/core/Mage/Catalog/Block/Navigation.php ./app/code/local/Mage/Catalog/Block/Navigation.php
wget -nv http://www.panticz.de/sites/default/files/magento/nav-container-mouse-over/Navigation.php.diff -O /tmp/Navigation.php.htmlChildren.diff
patch -p2 ./app/code/local/Mage/Catalog/Block/Navigation.php < /tmp/Navigation.php.htmlChildren.diff
 
# to complete disable mouse over change
        if ($hasChildren && $level == 0){
to
        if ($hasChildren && $level == -1){
in
./app/code/local/Mage/Catalog/Block/Navigation.php in line 223